BAMAKO, Mali — In life, he delighted in fomenting insurgencies in the African nations to the south. And in death, Col. Muammar el-Qaddafi is doing it all over again.

Hundreds of Tuareg rebels, heavily armed courtesy of Colonel Qaddafi’s extensive arsenal, have stormed towns in Mali’s northern desert in recent weeks, in one of the most significant regional shock waves to emanate directly from the colonel’s fall.

After fighting for Colonel Qaddafi as he struggled to stay in power, the Tuaregs helped themselves to a considerable quantity of sophisticated weaponry before returning to Mali. When they got here, they reinvigorated a longstanding rebellion and blossomed into a major challenge for this impoverished desert nation, an important American ally against the regional Al Qaeda franchise.

The Tuaregs hoisted their rebel flag in the sandy northern towns, shelled military installations, announced the “liberation” of the area and shouted “Allahu akbar,” or “God is great,” according to local officials. Their sudden strength has deeply surprised a Malian Army accustomed to fighting wispy turbaned fighters wielding only Kalashnikov rifles.

Months after the death of Colonel Qaddafi, his weapons have armed a rebel movement in Africa. In life he backed African insurgencies in Chad, Angola, Guinea-Bissau, Eritrea, Mozambique, Namibia and Zimbabwe.

And for this sparsely populated land, the recent fighting seems a step beyond the army’s desert skirmishes with the Tuaregs in the 1960s, the early 1990s and again in 2006. This time, the rebels are not being quickly stamped out or fleeing to the rocky mountains of this vast, inhospitable region. To the contrary, officials now say they are facing perhaps the most serious threat ever from the Tuaregs.

Emboldened by their new weaponry, they have formed a made-to-order liberation movement, the M.N.L.A., or Mouvement National Pour la Libération de l’Azawad — Azawad being the name they give to northern Mali.

“Our goal is to liberate our lands from Malian occupation,” said Moussa Ag Acharatoumane, one of the rebel spokesmen in exile in France.

The rebels — perhaps as many as 1,000, commanded by a former colonel in Libya’s army — brought with them enough of an arsenal to create a kind of standoff with the Malian Army.

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Tuareg rebels transported Libyan weapons back to Mali.Credit
The New York Times

Malian military officials agree. “Robust, powerful machine guns,” said Lt. Col. Diarran Kone of the Defense Ministry. “Mortars,” he added, describing the weaponry as “significant enough to allow them to achieve their objectives.”

About a half-dozen towns in the north have been attacked, including Niafounké. Both government and rebel forces have suffered casualties, and nearly 10,000 civilians have fled the fighting, according to the International Committee of the Red Cross.

The situation appears to have worsened for the Mali government over the past few days. The rebels have retaken the town of Ménaka, a military spokesman, Idrissa Traoré, acknowledged Friday, adding that a number of soldiers and civilians — he refused to say how many — had been killed by the rebels in the town of Aguelhok. In Bamako, the capital, families of soldiers have demonstrated against what they say is the government’s poor handling of the rebel offensive, blocking roads and burning tires. The defense minister has been replaced, and reprisals have been reported against Tuareg citizens living in the south.

Officials in Bamako make no secret of their shock at what one Western diplomat called the “robustness” of the rebel incursion.

“All of a sudden we found ourselves face to face with a thousand men, heavily armed,” said Mr. Maïga, the foreign minister. “The stability of the entire region could be under threat.”

The Malians, who viewed Colonel Qaddafi as a generous benefactor — he helped build an administrative complex here, among other things — now find themselves gnashing their teeth over this less beneficent aspect of his legacy. Still, officials here insist that the situation in the north is under control, while acknowledging that the threat is not over.

Analysts who study the region agree that the latest Tuareg resurgence is something new, and that Colonel Qaddafi is largely responsible, posthumously.

“This is a fairly significant military force,” said Pierre Boilley, a Tuareg expert at the University of Paris. “The game has changed. They can directly attack the Malian Army. I think the army will have trouble.”

The new Tuareg campaign “shows a pretty serious military and logistical capability,” said Yvan Guichaoua, a Sahara expert at the University of East Anglia, in Britain. The Tuareg spokesmen are cagey about disclosing the precise dimensions of their arsenal, hinting only that they owe Colonel Qaddafi a good deal. “The Libyan crisis shook up the order of things,” Mr. Acharatoumane said. “A lot of our brothers have come back with weapons.”

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Tuareg rebels on the lookout for government troops.Credit
Veronique de Viguerie

In some ways, the aggressive new Tuareg campaign represents the kind of support the rebels had long sought from Colonel Qaddafi, who for years alternately aided and betrayed the desert warriors, according to a recent study by Mr. Boilley. After the great regional droughts of the 1970s and 1980s, young Tuaregs migrated north to the colonel’s military training camps, to later fight for him in places like Chad, while at the same time destabilizing the governments in Niger and Mali.

Libya, with its World Revolutionary Center, where the warlords Charles Taylor of Liberia and Foday Sankoh of Sierra Leone were schooled in Colonel Qaddafi’s doctrines, became the regional matrix of instability.

The center’s mission was to “train volunteers in revolutionary warfare from all over the world,” according to a 1999 book by Stephen Ellis of the African Studies Center, in Leiden, the Netherlands, in keeping with Colonel Qaddafi’s belligerent anti-Western posture. The Libyan training camps under the center’s auspices “became the Harvard and Yale of a whole generation of African revolutionaries,” Mr. Ellis wrote.

Mr. Taylor, who is awaiting a verdict after a trial on war crimes charges, recruited his first troops there, leading to years of chaos in Liberia, while Mr. Sankoh’s murderous brigades also had a Libyan genesis, in part.

Colonel Qaddafi backed independence movements all over Africa, including a coup attempt in Sudan in 1976, and he supported pariah governments the West shied away from, like the military junta in Gambia in 1994.

His most significant African venture was in Chad during the 1980s, when he backed a rebel group against the government, with an eye toward capturing a mineral-rich border area. His surrogates were defeated by Chad’s government in 1987, but Libyan troops did not leave the disputed border strip until 1994.

Now, unwittingly, the picture is different. Outside a villa in Bamako recently, a dozen or more pro-government Tuaregs glumly contemplated the new order of things back home.

“When they came into Ménaka, they were yelling, ‘Allahu akbar.’ What does that mean? We don’t do that sort of thing when we fight,” said Bajan Ag Hamatou, a lawmaker from Ménaka. His brother, Aroudeïny Ag Hamatou, the mayor of a small town outside Ménaka, said, “A lot of buildings were destroyed.”

Bajan Ag Hamatou angrily blamed the West for having created a mess in his backyard.

“The Westerners didn’t want Qaddafi, and they got rid of him, and they created problems for all of us,” he said. “When you chased Qaddafi out in that barbaric fashion, you created 10 more Qaddafis. The whole Saharo-Sahelian region has become unlivable.”

A version of this article appears in print on February 6, 2012, on page A4 of the New York edition with the headline: Qaddafi’s Weapons, Taken by Old Allies, Reinvigorate an Insurgent Army in Mali. Order Reprints|Today's Paper|Subscribe